This invention relates to a film feeding device which winds up and rewinds film by means of an electric motor, in particular, to a film feeding device which efficiently feeds film by two frames.
Recently, in keeping with camera automation, the automation of film feed with a motor drive is promoted in the auto load (automatic loading), auto wind (automatic winding), and auto rewinding. Every function employs the method in which film is fed per frame in the direction of winding and is rewound upon completion of winding. Also, a preloading system is available which exposes the film while rewinding after the whole film has been wound up. The principle employed is the same as that above.
In these conventional devices, it takes several minutes to rewind and preload film because the whole film is rewound and woundup when the power supply voltage drops. This presents an obstacle if one wishes to shoot the succeeding object immediately. Also, when rewinding is suddenly activated and quietness is an issue in, for example, a wedding ceremony or concert, noise and time can be great inconveniences in a camera with an autoreturn device. To reduce rewinding time, film feed speed is increased. However, a great reduction of rewinding time cannot be expected due to the relation between the power supply and torque required. Also, it is impossible to eliminate noise completely; cost is also a factor in this.